Textile treatment



ment.

Patented Apr. l5, 1941 TEXTILE TREATMENT Paul Arthur, Jr., and MaxTheodore Goebel, Wilmington, Del., asaignors to 15.1.11]! Pont deNemours & Company, W poration of Delaware Application April 9,1940,eriai No. 328,766

11 Claims.

No Drawing;

This invention relates to the improvement of wool and more particularlyto reduction of its shrinking tendency.

Woolen textiles are characterized by their tendency to felt whensubjected to mechanical working. This felting tendency is, essential inthe finishing of some woolen goods to give a dense surface, and in themanufacture of felt for paper machine blankets, and the like. However,since it causes shrinking during laundering, it is a seriousdisadvantage in many wool applications. Considerable attention hastherefore been given to reducing or eliminating shrinkage due tofelting. For some applications, including knit goods, baby clothing,underwear, and socks, it is desirable to have the material substantiallycompletely shrinkproof. For overcoats, suits, dresses, blankets,Jacketsand other articles which are laundered less frequently the woolneed be only partially shrinkproof to be satisfactory'in practice.Previous shrlnkproofing methods, including treatment with chlorine,hypohalites, sulfuryl chloride, and the like, have not been entirelysatisfactory. Chlorination is difllcult to control and producesharshness and discoloration. Sulfuryl chloride is less objectionablefrom the standpoint of harshening effect, but it is inconvenient to usebecause of its strongly acidic nature, which necessitates the use ofspecial acid-resistant equipment in carrying out the treatment. Also,when, .as previously proposed, agents are used to treat union fabricsconsisting of both wool and cotton, the acid-sensitive celluloslc fibersare weakened as is shown by a marked decrease in the tensile strength ofthe fabric.

This invention has as an object the improvement of the physicalcharacteristics of wool by reducing its tendency tq shrink onlaundering. Another object is the production of a shrinkproof wool freefrom harshness and discoloration. A further object is the preparation ofthe product by a convenient process which may be carried out ininexpensive and readily available equip- A still further object is aprocess suitable for use on mixed wool-cotton material. Other objectswill appear hereinafter.

These objects are accomplished by the following invention wherein atextile comprising wool is treated with a dispersion, preferably asolu-' F tion, comprising an organic compound having at 11, Del., a cor-(Cl. 8-l28) valences attached to members of the group consisting ofcarbon and hydrogen, and an acidbinding agent, i. e., an acidneutralizing agent, e. g., a hydroxide, phosphate, bicarbonate,carbonate or alcoholate of an alkali or alkaline earth metal, a strongquaternary ammonium base, or tertiary aliphatic amine.

In carrying out the invention, wool or a woolcontaining textile isimmersed in a dispersion of the thiol compound in a suitable solventwhich also contains an acid-binding agent such as sodium hydroxide. Itis most convenient to use solvents in which both the thiol compounds andthe alkali are readily soluble, such as the alcohols or water. Ethylalcohol is very highly satisfactory, and methanol, isopropanol, butanol,etc., may also be used. Water is satisfactory as a solvent in the caseof the lower mercaptans, such as ethyl mercaptan, but is not as usefulfor higher mercaptans, such as cyclohexanthiol, because of the lowersolubility of these substances. The treatment is most convenientlycarried out at room temperature, and may be continued mostadvantageously for about one hour. After treatment, the excess solutionis removed by rinsing the fabric in water or in other solvent. It isalso possible to use wringers or centrifuges to remove the excesssolution.

The more detailed practice of the invention is illustrated by thefollowing examples, wherein parts given are by weight unless otherwisespecifled. There are of course many forms of the inv vention other thanthese specific embodiments.

Example I One part of wool flannel is immersed at 25 C. for one hour in10.2 parts of a.1.7% solution of cyclohexanethiol which also contains0.53% of sodium hydroxide in 95% by volume ethyl alcohol denatured with0.5% by volume of benzene. The treated fabric is then rinsed in waterand dried. This treatment completely removes the shrinking tendency ofthe wool.

In determining the shrinkproofness of the treated wool, it has beenfound convenient to use a uniform testing procedure, referred tohereinafter as the laundering test. In this test a small sample of woolfabric treated according to a process of this invention and a similarsample of untreated fabric are measured to determine their respectiveareas and then each is passed a definite number of times (usually 150)through a rubber-roll wringer,'dipping after each pass into a solutioncontaining 0.25% of a detergent, e. g., Ivory Soap or sulfated oleylalcohol and 0.1% sodium carbonate at 25 C. Other dilute alkaline soapsolutions can be used in this test. After laundering, the samples aredried and again measured. The area losses sustained by the samplesarethen determined and the per cent shrinkproofness is calculated fromthe following formula:

100mm loss of untreated fabric-area loss of treated fabric)- (area losof untreated iabric) Percent shrinkproolnese, i. e., percent red notionof tendency to shrink The per cent shrinkproofness given in thefollowing examples was determined by this method. The laundering test isalso a convenient method of following the shrinkproofing treatment sincea small sample may be taken from the textile material which is immersedin the mercaptan dispersion at the end of a period Judged to be suitablefor obtaining the desired eflfect and tested in the above manner todetermine the per cent shrinkproofness. If the material has not yet beentreated to the desired degree, the process may be continued untilanother test indicates that the desired degree of shrinkproofness hasbeen achieved.

Example II One part of wool crepe is immersed for one hour at 25 C. in5.5 parts of a 0.89% dispersion of formthional which also contains 0.35% of sodium hydroxide in 95% by volume ethyl alcohol denatured with0.5% by volume benzene. At the end of the treatment the solution isremoved by rinsing the fabric in water. The treated fabric isshrinkproof and free from tendering.

Example 111 One part of union fabric having a cotton warp and a woolwoof is immersed at C. for one hour in 4.5 parts of a 0.89% dispersionof formthional which also contains 0.35% of sodium hydroxide in 95% byvolume ethyl alcohol denatured with 0.5% by volume benzene. The treatedfabric is found to be substantially shrinkproof (90.5%) and free fromdiscoloration,

Example IV One part of wool flannel is immersed for one hour at 25 C. in6.4 parts of a 1.4% solution of ethanethiol in saturated lime water. Thefabric is then wrung dry and rinsed in water. The shrinking tendency ofthe flannel is greatly decreased (57%).

Example V Example VI One part of wool flannel is immersed for one hourat 25 C. in 7.5 parts of a 1.95% solution of cetanethiol which alsocontains 0.35% of sodium hydroxide in 95% ethyl alcohol denatured with0.5% by volume benzene. The excess solution is rinsed from the fabricwith solvent and the cloth is dried. A reduction in the shrinkingtendency is obtained as a result of this treatment.

Example VII One part of wool flannel is immersed for seventeen hours at25 C. in 6.4 parts of a 1.4%

solution of thiosemicarbazide in saturated lime water. A markedreduction (27.5%) in the shrinking tendency of the flannel is eifectedby this treatment.

In the process of the present invention, there may be used any organicsubstancewhich, when in a weakly alkaline solution, contains or yieldsat least one thiol (SH) group attached to aliphatic carbon. Because oftheir higher effectiveness, those substances are greatly preferred inwhich the thiol groups are attached to aliphatic carbon atoms which are,in turn, attached to other atoms only by single bonds. The followingtypes of substances are included in the preferred class:

(a) Aliphatic mercaptans such as ethyl, methyl, cetyl, n-propyl,isopropyl, n-propylbutyl, sec.-butyl, tert.-butyl, amyl and n-octylmercaptans, octanethiol-2, etc.

(b) Thioglycols, including monoand dithioglycols, e. g.pentamethylenedithiol and 2,2'-dimercaptodiethyl ether.

(0) Polythiols, including sym.-neopentanetetrathiol and thioglycerine.

(d) Alicyclic mercaptans, e. g., cyclohex'anethiol,methylcyclohexanethiols, and halogenated cyclohexanethiol.

(e) Heterocyclic mercaptans, e. g., 4-mercaptopyrane, and furfurylmercaptan.

(f) Aralkyl mercaptans, e. g., beta-phenylethyl mercaptan, in which thethiol group is attached to the aliphatic part of the molecule.

(g) Polymeric mercaptans, e. g., condensation products of aldehydes andhydrogen sulfide, e. g., that described in U. S. 1,991,765. Formthional,the material prepared by saturating a formaldehyde solution withhydrogen sulfide as described in this patent, is particularly preferredbecause of its great effectiveness and low volatility. Its chemicalformula is probably HSCH2(SCH2)1QCH2SH, wherein :c=1 to 5.

Other compounds useful in this invention, but much less preferredbecause of lower eifectiveness, include those which enolize underalkaline conditions to yield thiol groups, such as thiosemicarbazide.The N-dialkyl dithiocarbamates may also be used.

Thethiol compounds of this invention may contain other groups, such asamide or amine linkages, or also aromatic groups, provided the thiolgroups are attached to aliphatic carbon. The thiol and the product ofthe neutralization thereof by the acid binding agent in the solution areregarded as equivalents. However, the thiophenols, such asbeta-thionaphthol, are ineifective and are therefore excluded. All theabove thiol compounds can be prepared by well-known methods, and theirpreparation forms no part of the present invention. The thiol-containingmaterial used as the reagent in the treatment need not be pure, nor doesit have to be a chemical individual. Satisfactory results can beobtained by using crude mixtures of mercaptans such as those derivedfrom petroleum fractions or by using mixtures containing polymericthiols of various molecular weights. A perfect solution is preferable toprevent deposits on the material being treated, but very slightlysoluble thiol materials, such as formthional, may be used as suspensionsor dispersions, and give the desired degree of shrinkprooflng. While anysolvent may be employed, it is preferred that a solvent having at leastsome swelling action on the wool be employed. Hydroxylated solvents suchas bol and water are preferred.

A wide range of acid-binding agents may be used including the alkalimetal hydroxides, carbonates, bicarbonates, phosphates, and alcoholates,the corresponding alkaline earth compounds, e. g., barium, calcium,andstrontium hyalcobases, e. g.. tetramethyl ammonium hydroxide. Foreconomic reasons, it is preferred to use the cheap alkali metal oralkaline earth acid-binding agents rather than the organic compounds.

The solvent, wool to liquor ratio, temperature, and length of treatmentare interdependent variables. Thus it is possible to obtain satisfactoryshrinkproofing within a shorter period of time by increasing thetemperature and concentration of the treating agents. In most cases, itis preferred to adjust conditions so that a period of one-half to two.hours may be used to obtain satisfactory shrinkproofing treatments. Alonger period of immersion is undesirable because of operating costs andsome danger of lowering the tensile strength ofthe fiber.

The concentration of acid-binding agent is important in obtaining thebest results as is shown by the following table of treatments in whichthe wool is immersed one hour in 5.2 parts by weight of a 1.7% solutionof cyclohexane thiol in 95% by volume benzene-denatured ethyl alcoholcontaining varying p rcentages of sodium hydroxide.

Table 1 Weight percent of sodium hydroxide 13 30 67. 5 79- 5 in 95% byvolume ethyl alcoholdenatured with 0.5% by volume benzene.

' Table II Weight percent of sodium hydroxide Percent of shrinkprooiing23. 7 67. 4 76. 3 7i. 1 Completely sbrinkproof It should be noted fromthe above table that it is permissible to use widely varying percentagesof the acid-binding agent without seriously affecting the process. Ofcourse, it will be obvious to one skilled in the art of wool finishingthat abnormally excessive treating periods or acidbindlng agentconcentrations should be avoided.

It is preferred to use acid-binding agent concentrations within therange of 0.2-2% by weight based on the total weight of solutionemployed. Higher acid-binding agent concentrations cause a slightly lesssoft feel in the product, but are till useful, particularly when thewool is treated droxides, and the strong quaternary ammonium forperiodsof time shorter than two hours. Thus, as is shown in Table II,satisfactory shrinkproofing effects have been obtained by usingformthional and 5.8 percent of sodium hydroxide in alcohol for a'75'minute period. Even higher acid-binding agent concentrations areinconvenient to prepare in alcohol solvents and cause some loss oftensile strength, For these reasons they are not preferred' Acid-bindingagent concentrations of Ooh-0.2% by weight are useful wheresubstantially complete shrinkproofing is not essential. In any case theacid-binding agent concentration should be below that which would causeany substantial injury to the wool at the temperature and for the'timeemployed.

The process of the present invention is applicable to any textilecomprising wool, or a mixture of wool with other textile materialswhether in the form of fabric, yarns, or threads. Other finishingtreatments can be applied before or after the shrinkproofing treatment.Such finishes include the application of waterproofing agents, dyes,metallic salts, lubricants, or starch preparations.

To obtain best results, it is preferred to operate this invention atsubstantially room temperature, i. e., 15-35 C. although temperatures upto 50' C. may be employed.

Because of the widely different characteristics of the various kinds ofwool, it is obvious to one skilled in the art of wool treatment thataccount should be taken of these variations in carrying out anymodification of the fibers. The effectiveness of the shrinkprooflngtreatment for a specific woolen fabric is contingent on the correctbalance of a number of factors, including the choice of reagent,solvent, and acid-binding agent, the ratio of wool to thiol dispersions,the concentration of the reagents and the temperature and duration ofthe treatment. However, a few simple trials by one skilled in the artwill serve to indicate optimum treating conditions in any given.

case. It will be noted that the treatment durations and temperaturesused in the examples are those most suited to large-scale applications.

Wool, shrinkproofed bv the processes of this invention, is well suitedfor finishing treatments ing agents, oxidizing agents, alkylatingagents.

metallic salts, and the like.

The reagents of this invention offer the advantage over those hithertocommercially employed of being less dangerous and much less corrosive,so that it is not necessary to use special acid-resistant apparatus. Thereaction is slow enough to permit of easy control by varying theduration of the treatment and the concentration ,of the reagents. .Afurther advantage of this process over those hitherto employedcommercially is that it is suited for application to wool-cotton unionfabrics. Procedures previously employed for the shrinkproofing of woolare carried out under somewhat acidic conditions to which the cellulosiccomponents of the textile materials are sensitive. For example, a stripone inch wide of material treated as in Example III is found to have atensile strength of 80.2 pounds measured in the direction of the warp,consisting of cellulosic fibers. An untreated control has a value of82.0 pounds under the same testing conditions, indicating that thetreatment, described in Example III, has substantially no effect on thetensile strengthof the cotton component of the fabric. On the otherhand, the same fabric treatedlwith sulfurylchloride according to theprocess described below gives a tensile strength of only 65.2 poundsunder the same testing conditions, indicatiir; that serious damage hasbeen caused. The sulfuryl chloride treatment is carried out by immersinga union fabric ('7 parts) having a cotton warp and a wool woof at C. forone hour in 27 parts of a 2% by volume solution of the shrinkproofingagent in Stoddard solvent. The fabric is then freed from the excesssolution, rinsed first in water, then in 5% aqueous ammonium hydroxidesolution, and finally in water. The sample treated according to ExampleIII is 90.5% shrinkproofed whereas that treated with sulfuryl chloridewas 76% shrinkproofed.

The above description and examples are intended to be illustrative only.Any modification of or variation therefrom which conforms to the spiritof the invention is intended to be included within the scope of theclaims.

What is claimed is:

1. A process for reducing the tendency of a textile comprising wool toshrink which comprises treating the same with a dispersion comprising anacid-neutralizing substance and an organic compound containing at leastone thiol (-SH) group attached to a carbon atom. attached to three otheratoms by single bonds in which compound the non-thiol portion of themolecule is selected from the class consisting of aliphatic, araliphaticand cycloaliphatic hydrocarbon radicals, aliphatic hydrocarbon radicalscontaining ether groups and aliphatic hydrocarbon radicals containingthioether groups.

2. A process for reducing the tendency to shrink of a textile comprisingwool which com-" prises treating the same with a solution comprising anacid-neutralizing substance and an organic compound containing at leastone thiol (SH) group attached to a carbon atom attached to three otheratoms by single bonds in which compounds the non-thiol portion of themolecule is selected from the class consisting of aliphatic, araliphaticand cycloaliphatic hydrocarbon radicals, aliphatic hydrocarbon radicalscontaining ether groups and aliphatic hydrocarbon radicals containingthioether groups.

3. A process for reducing the tendency of a woolen textile to shrinkwhich comprises treating the same with a solution in an alcohol of anacidneutralizing substance and an organic compound containing at leastone thiol (-SH) group attached to a carbon atom attached to three otheratoms by single bonds in which compound the non-thiol portion of themolecule is selected from the class consisting of aliphatic, araliphaticand cycloaliphatic hydrocarbon radicals, aliphatic hydrocarbon radicalscontaining ether groups and aliphatic hydrocarbon radicals containingthioether groups.

4. A process for reducing the tendency of a woolen textile fabric toshrink which comprises treating the same with a solution of anacidneutralizing substance and an organic compound containing at leastone thiol (-SH) group attached to a carbon atom attached to three otheratoms by single bonds in which compounds the non-thiol portion of themolecule is selected from the class consisting of aliphatic, araliphaticand cycloaliphatic hydrocarbon radicals, aliphatic hydrocarbon radicalscontaining ether groups and aliphatic hydrocarbon radicals containingthioether groups.

5. A process for reducing the tendency of a woolen textile fabric toshrink which comprises treating the same with a solution, in ethylalcohol, of an acid-neutralizing substance and formthional.

6. A process for reducing the tendency of a textile comprising wool toshrink which comprises treating the same with a dispersion comprising anacid-neutralizing substance and formthional.

7. A process for reducing the tendency to shrink of a textile comprisingwool which comprises treating the same with a solution comprising anacid-neutralizing substance and formthional. I I

8. A process for reducing the tendency of a woolen textile to shrinkwhich comprises treating the same with a solution in alcohol of anacidneutralizing substance and formthional.

9. A process for reducing the tendency of a woolen textile fabric toshrink which comprises treating the same with a solution of anacidneutralizing substance and formthlonal.

10. A process for reducing the tendency of a union goods comprising woolto shrink which comprises treating the same with a solution, in ethylalcohol, 01 an acid-neutralizing substance and formthional. A p

11. Process of claim 10 wherein the union goods comprises anacid-sensitive textile material having a cellulosic nucleus selectedfrom the class consisting of cellulose and celluose acetate.

PAUL ARTHUR, JR. MAX THEODORE GOEBEL.

CERTIFICATE OF CORRECTION.

Patent No. 2, 58, 672

April 15, 19in.

' PAUL ARTHUR, JR. ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page iisecond column, line 15, claim it, for the word "compounds" read--compound-;

line 58, claim 8, before "alcohol" insert --an--;

and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Office.

. Signed and sealed this 1st day of July, A. n. 19in.

(Seal) Henry Van Arsdale,

Acting Commissioner of Patents.

